The regulations on the cleaning and sterilization of re-usable medical instruments, in particular surgical instruments, place stringent demands requiring that the surgical instrument be able to be dismantled. In particular, the shaft and the manipulating device can generally be separated from each other. The manipulating device generally has at least two grip parts that are movable relative to each other, of which one is coupled to the shaft, and the other to a transmission rod arranged in the shaft. A movement of the two grip parts relative to each other results in a movement of the transmission rod in the shaft.
The proximal end of the transmission rod is designed in particular as a coupling element for releasable mechanical coupling to a grip part of the manipulating device. With different shaft diameters, transmission rods with different cross sections are used. Particularly if the transmission rod is connected to a tool separable from the shaft and can therefore be pulled out of the shaft in the distal direction, the size of the coupling element at the proximal end of the transmission rod depends on the cross section of the shaft.
In medical instruments for microinvasive interventions, there is a trend toward ever thinner shafts. This requires ever smaller coupling elements at the proximal ends of the transmission rods. Manipulating devices conventionally used with the same design for many different medical instruments can therefore no longer be used unchanged. Instead, the manipulating devices have to be modified and, in the worst case scenario, have to be adapted again and again to ever smaller coupling elements at proximal ends of transmission rods.